Posted
by
samzenpus
on Monday September 30, 2013 @04:09AM
from the law-and-order-rat-mystery-club dept.

An anonymous reader writes "Ratting someone out' just became much more literal. Dutch police are using trained rats to help keep the streets clean. 'Detective Derrick and his rat partners cost just £8 each and are capable of being trained to identify an impressive range of odors—including drugs and explosives—within ten to 15 days. In contrast, a police dog costs thousands of pounds and requires a minimum training period of eight months. The training procedure is straightforward: the rats are kept in a cage with four metal tea strainers attached inside, one of which contains gunpowder. When the rat recognizes the smell, it is rewarded with a "click" and a small treat. Eventually the rat will learn to move towards the smell instantly. In a demonstration it takes Derrick just two seconds to locate the offending odor."

I find it remarkable and interesting that we still can't or at least not easily produce eith sensors the sniffing capabilities of these critters.

Aside from the fact that the answer would more or less inevitably involve some you-have-fun-fabricating-that micro to nanoscale arrangement of chemical receptors, we labor under the considerable difficulty that we don't really know how scent works.

With something like sight, it's possible to work more or less entirely independently of any real understanding of the eye, human or otherwise, because things like 'primary colors' and color mixing actually work pretty well at handling a wide variety of real-world problems and are simple enough that a decent art curriculum probably covered them before you finished high school. There are certainly horrible complexities ('metallic' isn't a color; but it certainly is a recognizable optical phenomenon, also, please characterize any deviations from the expected result when I take the idealized 24-bit RGB image displayed on my non-ideal 8-bit RBG monitor and send it over to my printer, using CMYK inks...); but 'just put a photosensitive material behind an array of R G and B filters' does actually work. If you proceed to brute-force the hell out of it, it works even better.

With something like scent, we know about plenty of strong and distinctive scents; but nothing 'primary'. Mixing is somewhere between unintuitive and pure black magic, prediction from chemical structures(even if perfectly well defined and provided in whatever form you prefer) is quite difficult outside of a few very well known areas, it's a total mess. Certainly, our ability to (cheaply and quickly, and from very small samples) analyze chemicals in the environment isn't as advanced as we would like; but even if it were, it's not as though we can see ourselves progressing toward the smelloscope, with some technical limitations (as we could in the early days of photography, were basically everything sucked; but basically everything was also precisely analogous to its better-refined contemporary chemical film systems), we'd just be better at identifying molecules flying around in the air.